Server Quality Checklist

Tool Scores

• get_aggregationsC
  2.4/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description must disclose behavioral traits. It states a get operation but doesn't explain what aggregations are, whether any filtering is applied, performance implications, or that it is read-only. The single sentence provides minimal insight beyond the tool's name.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness3/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single, short sentence that is direct and front-loaded. However, it is under-specified, so the conciseness comes at the cost of clarity. The structure is fine, but the content is minimal.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Although an output schema exists and may cover return values, the description is incomplete for a tool with 5 parameters and no schema coverage. It does not explain the purpose of aggregations, how they relate to STAC items, or any constraints or edge cases, leaving the agent without critical context for correct invocation.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters1/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0%, and the description does not mention any parameters. There are 5 parameters (collections, bbox, query, datetime, catalog_url) with no explanation of their roles, formats, or how they affect the aggregations. The description offers no compensatory value.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description uses a clear verb+resource structure ('Get aggregations for STAC items'), indicating a read operation on aggregated data. It is specific enough to distinguish from sibling tools like get_item or search_items, though it doesn't explicitly point out the distinction.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is provided on when to use this tool versus alternatives such as search_items or get_queryables. There is no mention of typical use cases, prerequisites, or conditions under which aggregations would be preferred.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• search_collectionsC
  2.4/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description must disclose behavioral traits. It only says 'Return a page,' which implies read-only and pagination, but does not explain pagination behavior, the role of catalog_url, or any output format. The agent is left guessing about side effects and edge cases.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness3/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The single sentence is concise and front-loaded, but it is under-specified. It earns its place as a purpose statement but omits necessary details, making the description too thin to be fully useful.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool has 2 parameters, no annotations, and an output schema, the description is incomplete. It fails to explain pagination semantics (limit), the effect of catalog_url, or how this tool fits within the broader STAC API workflow, leaving significant gaps for the agent.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters1/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0%, so the description must compensate by explaining the parameters. It mentions neither limit nor catalog_url, forcing the agent to infer their meaning solely from names, which is insufficient.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the action ('Return') and the resource ('STAC collections'), with a hint at pagination ('a page'). It distinguishes from sibling tools like get_collection (singular) and search_items (items) by focusing on collections as a whole.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is provided on when to use this tool versus alternatives. For instance, it doesn't clarify when to prefer search_collections over get_collection or search_items, nor mention any prerequisites or context like catalog_url.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• estimate_data_sizeC
  2.6/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description must fully disclose behavioral traits. It only states 'estimate' without saying whether this is a read-only operation, whether it makes network requests, how the estimate is computed, or if it has side effects. This is insufficient for a tool that may execute queries.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single sentence with no fluff and front-loads the main verb. However, it is so brief that it sacrifices necessary detail, but for pure conciseness it earns a high score.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given 9 parameters, no annotations, and an output schema that is not provided in context, the one-sentence description is insufficient. It does not explain return values, output format behavior, or the impact of parameters on the estimate.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters1/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0% and the description does not discuss any of the 9 parameters. The phrase 'STAC query' implies query parameters but gives no meaning to individual parameters like bbox, datetime, collections, limit, or output_format.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description uses a specific verb 'estimate' and identifies the resource as 'data size for a STAC query'. This clearly distinguishes it from sibling search and retrieval tools, though the term 'data size' could be more explicit (e.g., number of items vs total bytes).

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is provided on when to use this tool vs alternatives like search_items or get_aggregations. The description does not mention prerequisites, exclusions, or typical scenarios for use.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_rootC
  2.8/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations provided, the description carries the full burden for behavioral disclosure. It states 'Return,' implying a read-only operation, but it does not explain how catalog_url is used, what happens when it is null, or any network/error behavior. This minimal disclosure is insufficient for full transparency.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single, focused sentence that immediately communicates the tool's purpose. It contains no filler or redundant content, making it appropriately concise and front-loaded.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool's simplicity and the presence of an output schema, the description could still adequately cover usage and parameter semantics. However, it omits any explanation of catalog_url and lacks guidance on when to call this tool relative to siblings. The tool is simple, but the description leaves key gaps, especially regarding the optional parameter.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The schema has one parameter, catalog_url, with 0% description coverage, and the tool description does not mention this parameter at all. The phrase 'for a catalog' vaguely hints at its purpose, but the description adds no explicit meaning beyond the parameter name and type in the schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the verb 'Return' and the resource 'STAC root document for a catalog,' making the tool's function unambiguous. However, it does not explicitly distinguish itself from sibling tools like get_capabilities, which also return server-level resources, so it earns a 4 rather than a 5.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is provided on when to use this tool versus alternatives. The description only states the action and resource, with no mention of prerequisites, exclusions, or when it is appropriate to call get_root over other catalog-related tools.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• search_itemsC
  2.8/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the tool searches for items, without mentioning return format, pagination, authentication, or effects of parameters like catalog_url and sign_assets.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness3/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single sentence with no wasted words, but for a tool with 12 parameters and rich filtering capabilities, it underuses the opportunity to summarize key features. It is concise but not informative enough.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The tool has an output schema and complex parameters, but the description fails to address usage context, alternatives, or behavioral expectations. This is a minimal description for a complex search tool, leaving significant gaps in understanding.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 100%, so the schema already fully documents all 12 parameters. The description adds no additional parameter semantics, but the baseline of 3 applies because the schema does the heavy lifting.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description 'Search for STAC items' uses a specific verb and resource, clearly indicating the tool's core function. However, it does not differentiate from sibling tools like search_collections or get_item, which also operate on STAC data.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides no guidance on when to use this tool versus alternatives. Sibling tools such as search_collections and get_item exist, but no comparative context or exclusions are mentioned.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_conformanceC
  2.9/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description must disclose behavioral traits itself. 'Return server conformance classes' is minimal; it does not describe the effect of the check parameter returning booleans, the catalog_url override, or any side effects/read-only nature. This falls short of full transparency for an agent.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single concise sentence that is front-loaded and free of fluff. It is appropriately sized for a simple tool, though it is quite terse; this balances to a 4.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the low complexity, 100% schema coverage, and the presence of an output schema, the description provides adequate context for an agent to invoke the tool. However, it lacks any contextual framing about when conformance classes are needed or how they relate to other endpoints, keeping it at a 3.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 100%, with both check and catalog_url fully documented in the input schema. The description adds no additional parameter semantics, so per the baseline for high schema coverage, this scores a 3.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description 'Return server conformance classes' clearly identifies the action (return) and resource (server conformance classes). It does not explicitly differentiate from siblings like get_capabilities, so it earns a 4 rather than a 5.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides no guidance on when to use this tool versus alternatives such as get_capabilities. There is no mention of exclusions or preferred scenarios. The only implied usage is from the tool name itself, which does not constitute clear guidance.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_collectionB
  3.3/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description must disclose behavioral traits. It only says 'Fetch' implying a read operation, but provides no details on error handling, authentication, or consequences. This is insufficient for a tool with no annotation support.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is one short sentence, front-loaded with the key information, and contains no filler words.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The tool has an output schema, so return values are covered, but the description is minimal. It does not explain the catalog_url parameter or provide usage guidance, making it incomplete for a tool with no annotations.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0%, so the description should compensate. It clarifies that collection_id is the identifier, but catalog_url is not explained at all. The description adds minimal meaning beyond the parameter names.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the verb 'Fetch', the resource 'single STAC Collection', and the scope 'by id', which distinguishes it from sibling tools like search_collections (plural) and get_item (different resource).

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies usage when a specific collection id is known, but it does not explicitly mention alternatives or exclusions. It lacks guidance on when to choose this tool over search_collections or get_item.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_sensor_registry_infoA
  3.5/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations provided, the description carries full burden for behavioral transparency. It only says 'get information' and does not disclose whether the operation is read-only, what the response structure looks like, or any other behavioral traits beyond the obvious read intent.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single, clear sentence with no filler or redundant information. It is front-loaded and directly states the tool's purpose.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a simple parameterless getter, the description is minimally adequate, but it lacks context about what the STAC sensor registry is and why a user would invoke this tool. The existence of an output schema mitigates some ambiguity, but the description alone offers no additional context.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  This tool takes zero parameters, so schema description coverage is trivially 100%. The baseline score of 4 applies, and the description appropriately avoids discussing parameters that do not exist.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states that the tool retrieves information about the STAC sensor registry, using a specific verb and resource. It distinguishes itself from sibling tools such as get_root, get_conformance, and search_collections, which focus on different API aspects.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is provided on when to use this tool versus alternatives. The description simply states what it does, without any context about prerequisites, scenarios, or exclusions.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_queryablesA
  3.6/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  No annotations are provided, so the description must carry the full burden of behavioral disclosure. It only restates the basic function and implies a read-only action through 'Get', but it does not mention error behavior, collection existence requirements, the nature of the returned queryables, or how the optional catalog_url is used.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is a single, compact sentence that gets straight to the point. It has no filler or redundant phrasing, making it easy to parse and front-loaded with the core action.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  An output schema exists, so return values need not be described. However, the description omits the optional catalog_url parameter and does not address the array-vs-singular ambiguity in collection_id. For a low-complexity tool this is minimally adequate, but it leaves clear gaps in parameter understanding.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0%, and the description only partially compensates. It clarifies that collection_id identifies the collection, but the schema declares it as an array of strings while the description says 'specific collection' (singular), creating ambiguity. The optional catalog_url parameter is not mentioned at all, leaving its purpose unexplained.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description uses a specific verb ('Get') and resource ('queryable properties') scoped to a specific STAC collection by ID. This clearly distinguishes it from sibling tools such as get_collection, search_items, or search_collections, which deal with different resources or operations.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description makes the context clear: use this tool when you need queryable properties for one named collection. It doesn't explicitly state alternatives or exclusions, but the sibling list and the phrasing provide enough situational guidance for an agent to choose this tool appropriately.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_itemA
  3.7/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description carries full burden for behavioral disclosure. It only says 'Get' without specifying whether it's read-only, what happens if the item is not found, whether it requires authentication, or how the response is formatted (though some is in schema). Minimal transparency beyond the basic operation.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Single concise sentence with no redundant words. Front-loads the action and resource. Perfectly sized for the information it conveys.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool's relative simplicity, an output schema exists, and parameter descriptions are complete, the description is adequate but not rich. It lacks guidance on when to prefer this over search_items or how optional parameters like sign_assets operate, though schema covers mechanics. Somewhat complete but not fully contextual.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 100%, so the schema documents all 5 parameters. The description adds no extra meaning beyond naming the two required parameters (collection and item ID). Baseline 3 is appropriate; no additional semantic value provided.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the action ('Get'), the resource ('specific STAC Item'), and the key identifiers ('collection and item ID'). It distinguishes from sibling tools like search_items (search) and get_collection (collection-level), making the purpose unambiguous.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies when to use it: when you have a known collection ID and item ID. It doesn't explicitly mention alternatives or exclusions, but the word 'specific' and inclusion of both IDs clearly contextualize direct retrieval versus search. No misleading guidance.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• get_capabilitiesA
  4/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  With no annotations, the description carries the burden of explaining behavior. It discloses that the tool maps conformance classes to human-readable names and provides examples (query, sort, fields, aggregations), but it does not mention any side effects, permissions, or output structure details. This is adequate but not rich, so a score of 3 is appropriate.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is two sentences, front-loaded with the primary action, and every sentence adds value. The second sentence enriches the first with concrete examples, containing no wasted words.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The tool has only two optional parameters, an output schema, and a relatively simple purpose. The description provides sufficient overview and context (mapping behavior and examples) to understand when and why to use it. The presence of an output schema lessens the need to describe return values, so a score of 4 is justified.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Input schema coverage is 100%, with clear descriptions for both parameters (catalog_url and output_format). The tool description does not add any additional meaning to these parameters; it only describes the overall capability mapping. Since the schema already fully documents the parameters, the baseline of 3 is warranted.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose: 'Return a summary of STAC API capabilities.' It also adds specificity by explaining the mapping from conformance classes to human-readable capability names, which distinguishes it from the sibling get_conformance tool.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The phrase 'making it easier for agents to discover what features a catalog supports' gives clear usage context. It does not explicitly name alternatives, but the contrast with raw conformance listing is implied, which is sufficient for a guidance score of 4.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.